In general, a vehicle has mirrors mounted on the outsides of left/right front doors, the front left/right points of a bonnet, and the inside of a vehicle so that a driver can easily check road situations on the left, right, and rear sides. The mirrors are referred to as room mirrors and side mirrors, depending on the mounting locations thereof. That is, the mirrors located at the outsides of left/right front doors or front left/right points of a bonnet in the vehicle are referred to as the side mirrors.
A driver may recognize driving directions or speeds of other vehicles moving behind through the side mirrors while watching the road ahead on the left and right sides. Therefore, the driver may keep a safety distance from vehicles ahead or behind, and may also safely pass other vehicle moving behind, or change traffic lanes without interfering with the driving of the other vehicles.
Basically, the side mirrors include plane mirrors which are in a plane shape and thus easily manufactured. However, there has been an increasing demand for side mirrors which include convex mirrors in a convex shape so as to allow a vehicle driver to ensure a wider viewing angle, thereby widening the driver's field of view. Such convex mirrors have a wider field of view, compared to the plane mirrors, but have problems in that a driver's judgement may be impaired since objects look smaller due to a high reduction magnification, and an image may be distorted due to spherical aberration.
To solve the problems of the plane mirrors and the convex mirrors, an assistant mirror may also be further mounted on the vehicle. However, since an image is severely changed through a border area for installation of the assistant mirror, the assistant mirror has a problem in that it does not rather provide a sense of rear vision. Therefore, two areas through which a rear object is viewed at a fixed size need to be expressed on one side mirror while minimizing optical distortion.
By way of an example, Korean Registered Utility Model Publication No. 20-0288548 discloses a side mirror which includes an area directed toward a vehicle body and formed in a plane shape and an outside area formed as a plane of curvature in a convex shape. Korean Registered Utility Model Publication No. 20-0322014 discloses a side mirror which includes a plane mirror provided adjacent to a vehicle body and a convex mirror provided relatively far from the vehicle body.
However, such techniques also have problems in that it is difficult to expect a wider field of vision since the expansion of vision depends only on the curvature of the convex mirror far from the vehicle body, and the convex mirror provides an inaccurate sense of distance to an object, compared to the plane mirror, since the convex mirror has a characteristic in which an object looks smaller and looks far away from the center to the edge thereof.